There are a number of excitation pathways for organic molecules in water across the spectrum. These resonances will, generally speaking, relax thermally. Of c

There are a number of excitation pathways for organic molecules in water across the spectrum. These resonances will, generally speaking, relax thermally. Of course, the medium is salt water, so dielectric heating is the dominant effect of kHz - GHz RF irradiation, far above and beyond whatever heat is dissipated by the absorbance of distinct molecular resonances.